Air pollution and incidence of gastric and upper aerodigestive tract cancer in 15 European cohorts

Introduction: Associations with smoking and occupational exposures indicate that air pollution could be associated with increased risk of gastric and upper aerodigestive tract (UADT) cancers. However, data from large cohort studies is lacking. We evaluate the association between long-term exposure to ambient air pollution and gastric and UADT cancer incidence in European adult populations. Methods: Baseline addresses of individuals were geocoded and air pollution was assessed by land-use regression models for particulate matter (PM) below 10 µm (PM10), below 2.5 µm (PM2.5), between 2.5-10 µm (PMcoarse), PM2.5absorbance in 12 cohorts and for nitrogen oxides in 15 cohorts, and two traffic indicators. We used Cox regression models with adjustment for potential confounders for cohort-specific analyses. Combined estimates were determined with meta-analyses random effects models. Results: We included data on 305,319 individuals contributing 4,303,965 person-years at risk (average follow-up 14.1 years). 743 inci...